Flow-control system



C. W. LARN ER FLow CONTROL SYSTEM Filed March 17, 1920 Feb. 24. l 925.

Patented Feb. 24, 1925.

TIE

CHESTER W. LARNER, 0F PHILADELPHIA, PENNSYLVANIA, SSGNOR T0 THE JW111-LIAM CRAM @a SONS SHIP & ENGNE BUILDING COMPANY, A CORPORATION OFPENNSYLVANIA.

FLOW-CONTROL SYSTEM.

lApplication'filed March 17, 1920. Serial Noi.v 366,676.

To all whom t'mag/ concern: i

Be it known that I, CHESTER W. LARNER, a citizen of the United States,residing at Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented certain new and useful Improvements inFlow-Control Systems, of whichthe` following is a specification.

This invention relates to ilow control systems andv particularly to avalve control means for the ilow through water mains. The chief objectof the invention is to provide simple and eiiicient means for governingthe movementof a main control valve so that its degree and rate ofopening or -closing are at all times under complete control.

To avoid water hammer or sudden rushes of flowin the operation of watermain valves it is often necessary to move the Valve slowly when near itsseat though the remainder of thel valve stroke may be at any desiredrate. For instance in opening the valve of a hydraulic power system, atoo quick opening of the valve may admit the full flow suddenly intoempty spaces with great rush of ilow and abrupt stopping as the spacesare filled and resultant dangerous rise in pressure. In such case theproper operation is to open the control valve slightly and hold itpartially open until the empty spaces are filled or primed after whichthe opening movement of the control valve may be resumed at any desiredrate.

Similarly in closing the valve it is usually the last portion of theclosing movement that most suddenly` decelerates the llow and causeswater hammer and by easingoff or damping this closing movement in itsFinal phases the deceleration of the stream will be suliiciently gradualto avoid' dangerous rise in pressure.

In the apparatus of this invention the main control valve a't any pointin its opening or closing may be readily slowed down or stopped and thenagain accelerated so that the operator is enabled to exercise thedesired control and eilect the proper damped or interrupted movement ofthe valve. The movement of the valve is synchronous with the movement ofthe operating mechanism.

1n the accompanying drawings illustrating one embodiment of theinvention,

Fig. 1 is a diagrammatic plan viewof a water main control system andFig. 2 is vertical sectional view on line 2 2 of Fig. 1.

In the specific embodiment of the invention illustrated in theaccompanying drawings a water power main 1, 2 is provided with anenlarged portion 3 within which moves a valve plunger 4 seating at 5across the neck of the enlarged portion 3 to close the main `and movingback in cylinder 6 to open the main. The valve plunger 4 is hollow and yp in cylinder 6 and the body of the valve 4 is of reduced diameterproviding a space S between the piston 7 and the end- 9 of the cylinder6. A by-pass 10 is provided for admitting liuid pressure from the waterway 12 into the space 8 when the valve 'plunger is in its closedposition and an opening 13 is provided in the cylinder 6 for admittingfluid pressure from the water way 12 to the space 15 on the other sideof the valve plunger 4 and Within the cylinder 6.

The annular space 8 is connected to eX- haust through a valve 24 and thespace 15 is similarly connected to exhaust through a valve 23 whileanother outlet from this space 15 is provided by the opening 20 in thenose of the valve plunger 4 controlled by valve 21. Valve 23 iskconsiderably larger in flow capacity than port 13 in order that pressuremay be exhausted from chamber 15 by valve 23 notwithstanding thesimultaneous admission of pressure through port 13. To open valveplunger4 valve 23 is opened to exhaust pressure from chamber. 15whereupon pressure through/by-pass 1() into annular space 8 againstpiston 7 will begin the opening movement of the valve plunger 4, valve24 being closed. The partial opening of plunger 4 will close by-pass 10by the end 9 of the cylinder 6 and thereprovided with piston 7 movingafter pressure for the annular chamber 8 the plunger 4 in its openpositionv by eooperation with valve 21 in a manner here1n after morespecifically described. To close plunger 4 valves 21 and 23 are closedand valve 24vopened so that pressure will be exhausted from the annularchamber 8 and admitted through the port 13 behind the plunger to closeit.

Controlling of the port 13 and by-pass 10 being automatic by themovements of the plunger 4 the governing of valve plunger 4 is effectedby the operation of valves 21,

and 24 and to place this control conveniently7 in the hand of theoperator so that by movement of a. single control member he may properlycoordinate the movements of these valves. mechanism is provided which inthe specific embodiment shown in the drawings comprises an operating rod30 moved upward to cause a closing movement of plunger 4 and downward tocause an opening movement of the same. To the rod 30 is pivoted afloating lever 31 connected at the end 32 to mechanism controlling thevalve 21 and at the end 33 to mechanism alternatively controlling thevalves 23 and 24. The end 32 of the lever 31 is connected by link 34 toarm 35 of shaft 36 passing into the space 15 within the cylinder 6 andcarrying at its inner end the arm 37 linked by rod 38 to the valvemember 21 sliding in bearing 39 in plunger 4. It is obvious that upwardmovement of the rod 30 will draw upward on link 34 to tip arm 37 to theright (Fig 2) to shut valve 21. Upward movement of operating rod 30 willalso draw upward on link 41 and turn counter-clockwise arm 42 and leveror walking beam 43 both of which are connected to a rotatable stud 44 ina bearing 45 supported by the valve casing. The downward movement of theleft end of lever 43 closes valve 23 while the upward movement of theright end of lever 43 opens valve 24 so that the shutting of valve 21 isaccompanied by the opening of valve 24 and the closing of valve 23 andit is obvious that the main valve plunger 4 will be caused to move in adirection to close.

Valves 23 and 24 are preferably of the plunger type shown having theirplungers 53 and 54 controlled by rods 63 and 64 respectively extendingupward through the forked ends of lever 43 and downwardly spring pressedby springs `48 and 58 so that both of the valve rods '63 and 64 arenormally pressed downward andboth the valves 23 and 24 normally closed.

With the linkages as above described and following a. slight upwardmovement of operating rod 30 it is apparent that the resultant closingof the plunger 4 will permit the arm 37 to tip counter-clockwise (Fig.2) letting the floating lever 31 turn clockwise and with it the lever 43also clockwise so as to lower control rod 64 of valve 24 to restrictsaid valve, the previous counter-clockwise movement of lever 43 havingcompressed spring 58 and raised'said rod. Unless the operating rod 30 isfurther moved upward then the closing movement of valve plunger 4 willautomatically close valve 24 to restrict the outflow from the space 8and stop the closing movement of the plunger. The operator therefore byproper manipulation of the rod 30 may move the plunger 4 to any extentdesired. The rate of movement of the valve 4 is also dependent on therate of operation of rod 30 and it may he preferable in installationswhere there is danger of excessive rise in pressure upon ytoo suddenmovement of the valve 4, to limit the rate of movement of the operatingrod 30 in the hands of the operator so that a certain rate `of movementof the valve 4 cannot be exceeded.

When the closing movement of the valve plunger 4 is completed by theseating of.

the. valve if the final increment of the valve movement which permitsrod 38 to move to the right (Fig. 2) to tip the lever 43 clockwise doesnot permit control rod G4 to entirely close plunger 54 of valve 24 underthe action of spring 58 then lthe movement of rod 30 should be reversedslightly by the operator until valve 24 is permitted to close so thatall the valves 21, 23 and 24 will in the closed position of the plunger4 be normally closed while the port 13 and by-pass 10 will be open.

To open the valve plunger 4 the operator moves operating rod 30 downwardtending to draw valve 21 open and at the same time tending to turn lever43 clockwise to draw up control rod G3 against the compression of spring48 and thus open the plunger 53 of valve 23 so that pressure isexhausted from the chamber 15 while it is admitted to Chamber 8 throughliv-pass 10. lVhen operating rod 30 is drawn downward rthe first eHectis to transmit a pressure to rods 34 and 41 thus pressing the left endof lever 43 up against the enlargement 49 of rod 63 and tending "tocompress spring 48. At the same time the pressure on rod 34 istransmitted through the various connections to valve 21 and if theadjustment of spring 48 gives sutficient resistance, valve 21 will hepulled off its seat before rod (i3 is lifted. ln this `case valve 21will open until it is stopped by bearing 39 and then valve 23 will beopened, but otherwise valve 23 will open first starting the plunger openand valve 21 would open only when the pressure on the outside of theplunger nosehas accumulated suiieiently.

This operation, of course, at the same time leaves valve 24 closed bythe pressure of spring 58 and if the operator continues the downwardmovement of rod 30 the openliti ing movement of the main plunger 4 willcontinue in a way similar to that already described for the lclosingmovement of the plunger. In eitherv case if the plunger is eithercompletely opened or fully closed the motion of rod 30 should beslightly reversed to restore walking beam or lever 43 to its horizontalposition and permit valve 23 or valve 24 to close. f

In valves of the type described it is of course important that plunger4should be held positively in both the open and closed positions so thatit cannot accidentally drift closed when it is open or drift open whenit is closed.A Furthermore this result should not be accomplished by acontinuous exhaust of pressure through valves 23 and 24 because of thewater waste which would result and also because of the destructioneffects of continuous flow through the valves.

Valves 23 and 24 should always be closed except when plunger 4 is inoperation. With valves 23 and 24 closed if plunger 4 is closed it willbeheld in that position by the unbalanced pressure of the conduitapplied on the entire area of the plunger seat and it is impossible forplunger 4 to open accidentally.. When plunger 4 is open, however, it canbe held in that position only by its own inertia and such difference ofpressure inside. and outside of plunger 4 as may be effected withoutopening valve 23. When plunger 4 is open and there is no flow in theconduit the pressure in chambers 15 and 8w and waterway 12 is equalizedby leakage communication between them and plunger 4 is held open onlydue to its weight. This, however, is sufficient since there is notendency for it to close in still water. If, however, water is flowingthrough Ithe valve the pressure communicated to chamber 15throughrrestricted port 13 will be higher than the' pressure exerted bythe Howing water on the outside of plunger 4 because the velocity offlow at the former point is lower than at the latter and unless somemeans be provided for equalizing these pressures the plunger 4 mayVstart to close and automatically open valve 23 by means of theconnectionsbetween plunger 4fa'nd valve 23. This tendency is correctedin the valve described by the use of valve 21 which is so connected torod V30 thatY when plunger .4 is open valve 21 -is also, open. thusequalizing the pressures inside` and outside of the plunger 4 or, ifsuitablyk designed, reducing the pressure in chamberV 15 below that onthe outside of the plunger nose by utilizing the suction effect of theflowing water on the nozzle in the nose of the plunger. This effect ismore readily accomplished by restricting the pressure supply throughport 13 but port 13 cannot be entirely cut o by plunger 4 in its open.

position because there would then be no means of supplying fluid tochamber l5 to begin the closing movement of plunger 4.

This system of control combines two alternative sets of movements. Whenvalve 23 is open valve 24 is necessarily closed and when valve 24 isopen valve 23 is necessarily vclosed and similarly whenpressure isapplied to open valve 21 it is also necessal-ily applied to open valve23 and close valve 24 and when the pressure is exerted to close valve 2lit is also exerted to open valve 24 and close valve 23. Thisdistribution of thekvalve movements is automatically attended to by themechanism shown without any-attention on the part? of the l operator whosimply moves the control rod 30. The movement of the valve may beinterrupted at any point and the rate of movement is necessarilydependent upon the rate of movement of operating rod 30 so that in thehands of a skillful operator the plunger 4 may be rapidly moved whenaway from its seat witha damping orinterruption of the movement whennear its seat. This system may therefore be utilized to secure both thepriming and damping characteristics often necessary to avoid undue risein pressurein the system and at vthe same time the remainder ofthe'valve movement may approximate closely the highest desired rate.

I cl-aim:-

l. In a system for controlling the flow of a fluid the combination witha main valve, of a control member therefor, a floating differentialelement actuated by said control member and mechanism operatedalternatively by said element to open or close said main valvecomprising alternatively operated fluid pressure valves.

2. In a flow control system the combination with a nrain: valve, offluid pressure control means therefor comprising plurality ofalternatively operated valves and another valve operable -alternativelywith one of said plurality of valves, and means for automaticallycontrolling the interaction of said valvesi 3. Ina flow control systemthe combination with a main valve, of fluid pressure control meanstherefor comprising a plurality of alternativelyy operated valves, acooperating valve and a floating differential ele-l ment selectivelyactuating certain of said valvesand dependently controlling theoperation of said coopera-ting valve.

4. In a flowcontrol system l"the combina- 'tion with a mainvalve, ofmeans for closing or opening said valve comprising an operating member,a floating differential element actuated thereby, and fluid pressurecontrol means comprising valves cooperating in -altern'ative sets andycontrolled by said member. l

5. In a system for controlling'the flow of a fluid the combination witha main valve having a piston portion with fluid pressure chambers onopposite sides thereof, of valves controlling the exhaust of pressurefrom said respective chambers, and fluid pressure means for operatingsaid valves comprising a connection to said main valve adapted to limitthe movement of the main valve by a predetermined movement of saidoperating means. y i

6. In a iioiv control system the combination with a main conduit valvehaving op,

positely acting fluid pressure chambers and permanent connectionspermitting conduit pressure to separately1 pass to said chambers, ofexhaust valves of' greater discharge capacity than said pressureconnections and adapted to alternatively exhaust the pressure from saidchambers, and means for operating said v-alves comprising a controlmember relatively movable with respect to said exhaust valves duringmovement of the main valve to limit the movement of the main valveaccording to the movement of the control member.

7. In a flow control system the combination with a main conduit valvehaving a tapering end and a passage therethrough connecting the interiorof said main valve with the fluid in said conduit, a valve con-4trolling said passage, a second valve con- 9. In a flow controlsystemgthe combina-y tion with a main conduit valve having a pistonportion between fluid pressure chambers and means permitting pressure topass from said conduit to said chambers, of valves for alternativelyexhausting the pressure from said chambers, and fluid pressure meansAfor operating said valves comprising a floating differential leverconnected to the main valve to limit the movement of the main valveaccording to the movement of the control means.

10. In a flow control system the combination with a main conduit valvehaving oppositely acting fluid pressure chambers and a tapered end withan opening from one ot' said chambers to a region of low pressure in thefluid way, of permanently open high pressure connections to saidchambers from said fluid way, a valve for said low pressure opening fromone of said chambers, an exhaust valve for the other of said chambers,and control means alternativelyfoperating said valves and automaticallyactuated by movement of. J[he mainl valve to limit the movement of themain valve according to a predetermined movement of the 'control means.I

ll. In a llow control system the combina-- tion with a main conduitvalve having op-` positely acting fluid pressure chambers Aand meanspermitting pressure to pass from said conduit to said chambers, ofvalves for alternatively exhausting -the pressure from said chambers,and fluid pressure means for operating said valves comprising a floatingdifferential member connected to the main valve to automatically.hydraulically balance said main valve and limit the movement of the mainvalve according to the movement of the controlmeans.

l2. In a flow control system the combination with a main conduit valvehaving oppositely acting fluid pressure chambers permanently open topressure from the Vfluid way, of exhaust valves for said chambers andoperating means for said exhaust valves f comprising a single memberalternatively lopening said exhaust valves and connected to said mainplunger so as to be movable therewith to automatically hydraulicallylimit the movement of said plunger according to a predetermined movementof said control means.

13. In a flow control system the combination with a main valve forcontrolling` the ow through a conduit, of fluid pressure operating meanstherefor, a plurality of valves controlling the movement of said mainvalve, a lever for alternatively opening one or the other of a pair ofsaid valves, a second lever for alternatively actuating another valveand said first named-lever and an operating member for actuating saidsecond named lever.

CHESTER W. LARNltR.

